Atrial fibrillation (AF) has been linked to left atrial (LA) enlargement. Whereas most studies focused on 2D-based estimation of static LA volume (LAV), we used a fully-automatic convolutional neural ...network (CNN) for time-resolved (CINE) volumetry of the whole LA on cardiac MRI (cMRI). Aim was to investigate associations between functional parameters from fully-automated, 3D-based analysis of the LA and current classification schemes in AF. We retrospectively analyzed consecutive AF patients who underwent cMRI on 1.5T systems including a stack of oblique-axial CINE series covering the whole LA. The LA was automatically segmented by a validated CNN. In the resulting volume-time curves, maximum, minimum and LAV before atrial contraction were automatically identified. Active, passive and total LA emptying fractions (LAEF) were calculated and compared to clinical classifications (AF Burden score (AFBS), increased stroke risk (CHA.sub.2 DS.sub.2 VAScgreater than or equal to2), AF type (paroxysmal/persistent), EHRA score, and AF risk factors). Moreover, multivariable linear regression models (mLRM) were used to identify associations with AF risk factors. Overall, 102 patients (age 61±9 years, 17% female) were analyzed. Active LAEF (LAEF_active) decreased significantly with an increase of AFBS (minimal: 44.0%, mild: 36.2%, moderate: 31.7%, severe: 20.8%, p<0.003) which was primarily caused by an increase of minimum LAV. Likewise, LAEF_active was lower in patients with increased stroke risk (30.7% vs. 38.9%, p = 0.002). AF type and EHRA score did not show significant differences between groups. In mLRM, a decrease of LAEF_active was associated with higher age (per year: -0.3%, p = 0.02), higher AFBS (per category: -4.2%, p<0.03) and heart failure (-12.1%, p<0.04). Fully-automatic morphometry of the whole LA derived from cMRI showed significant relationships between LAEF_active with increased stroke risk and severity of AFBS. Furthermore, higher age, higher AFBS and presence of heart failure were independent predictors of reduced LAEF_active, indicating its potential usefulness as an imaging biomarker.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Atrial fibrillation (AF) is associated with changes in left atrial (LA) volume, but the relationship between LA size, AF burden, and electrical conduction behaviour is still uncertain. The aim of ...this study was to quantify the association and impact of these parameters on the single-procedure outcome after circumferential antral ablation for pulmonary vein isolation.
Left atrial assessment was performed in 129 consecutive patients using pre-procedural imaging in three dimensions (sphericity, indexed volume), two dimensions (diameters), and from echocardiography in one dimension (long axis). Atrial fibrillation burden was classified based on the clinical assessment as paroxysmal and persistent and based on a validated scoring system including frequency, duration of AF episodes, and number of cardioversions into four grades (minimal, mild, moderate, and severe). P-wave duration and PR interval was measured on the 12-lead electrocardiogram at the end of the procedure. Atrial fibrillation burden score (AFB) was minimal (2%), mild (75%), moderate (9%), and severe (14%) and 65% had paroxysmal and 35% had persistent AF. The recurrence rate was significantly higher in patients with persistent AF, with higher AFB, with prolonged P-wave, and with an indexed LA volume > 55 mL/m2. In multivariable analysis, AFB (hazard ratio: 2.018(1.383-2.945), P > 0.001) and a prolonged P-wave (hazard ratio: 2.612(1.248-5.466), P = 0.011) were identified as significant predictors for AF recurrence.
In our cohort of patients with symptomatic AF, the AFB and the P-wave duration but none of the anatomical parameter revealed to be independent predictors for AF/AT recurrence after circumferential antral pulmonary vein isolation.
Artificial intelligence can assist in cardiac image interpretation. Here, we achieved a substantial reduction in time required to read a cardiovascular magnetic resonance (CMR) study to estimate left ...atrial volume without compromising accuracy or reliability. Rather than deploying a fully automatic black-box, we propose to incorporate the automated LA volumetry into a human-centric interactive image-analysis process.
Atri-U, an automated data analysis pipeline for long-axis cardiac cine images, computes the atrial volume by: (i) detecting the end-systolic frame, (ii) outlining the endocardial borders of the LA, (iii) localizing the mitral annular hinge points and constructing the longitudinal atrial diameters, equivalent to the usual workup done by clinicians. In every step human interaction is possible, such that the results provided by the algorithm can be accepted, corrected, or re-done from scratch. Atri-U was trained and evaluated retrospectively on a sample of 300 patients and then applied to a consecutive clinical sample of 150 patients with various heart conditions. The agreement of the indexed LA volume between Atri-U and two experts was similar to the inter-rater agreement between clinicians (average overestimation of 0.8 mL/m
with upper and lower limits of agreement of - 7.5 and 5.8 mL/m
, respectively). An expert cardiologist blinded to the origin of the annotations rated the outputs produced by Atri-U as acceptable in 97% of cases for step (i), 94% for step (ii) and 95% for step (iii), which was slightly lower than the acceptance rate of the outputs produced by a human expert radiologist in the same cases (92%, 100% and 100%, respectively). The assistance of Atri-U lead to an expected reduction in reading time of 66%-from 105 to 34 s, in our in-house clinical setting.
Our proposal enables automated calculation of the maximum LA volume approaching human accuracy and precision. The optional user interaction is possible at each processing step. As such, the assisted process sped up the routine CMR workflow by providing accurate, precise, and validated measurement results.
We aim to compare factors influencing safety, success rate and radiation dose of CT-guided biopsies and drainages in a non-teaching setting with experienced operators
a teaching setting with ...residents.
A total of 1021 cases were retrospectively analyzed regarding lesion size, distance from skin, procedure duration, radiation dose, complications and clinical success. Procedures were grouped into biopsies of lung, liver, (remaining) abdomen, musculoskeletal system (MSK) and drainages of any region. Procedures in non-teaching setting were performed by experienced operators (full time interventional radiology staff), teaching setting consisted of residents under supervision of interventional radiology staff.
Overall clinical success rate was 93.6 % experienced (exp.)
teaching setting: 93.5 and 93.6 %,
= 0.97. Overall complication rate was 7.2% (5.7% minor, 1.6% major; exp.
teaching: 8.0 and 6.5 %,
= 0.67. Experienced operators performed chest and liver biopsies faster even though they were facing smaller lesions. Multiple regression analysis revealed that depth from skin significantly increased procedure duration by 36.8 s per cm (
< 0.001) and also radiation dose by 5.4 mGy per cm (
< 0.001) in all interventions. On average, teaching setting increased the duration of an intervention by 209.8 s and total radiation dose by 10.6 mGy (
< 0.001,
< 0.001 respectively).
CT guided interventions can be performed safe und successful disregarding anatomical parameters or teaching setting. Depth from skin and teaching setting should be taken into account both from a clinical and a time-conscious point of view since they increase radiation dose and prolong operations.
This is the first study with >1000 interventions which shows and quantifies the impact of lesion depth and teaching setting in CT-guided interventions.
•Data on atrial fibrillation (AF) recurrence after multiple-procedure pulmonary vein isolation (PVI) are rare.•After up to two procedures (PVI only), left atrial volume predicts AF recurrence.•Burden ...based classification (AF burden score) predicts AF recurrence as well.•But conventional classification (paroxysmal or persistent) does not.
Catheter ablation of atrial fibrillation (AF) by means of pulmonary vein isolation (PVI) focuses on the PVs as the putative trigger of AF. However, which classification should be used to identify patients that are most suitable for PVI is uncertain. The aim of the study was to evaluate rhythm-, burden-, and anatomically-based classification schemes to predict success rates after up to two procedures of an ablation strategy strictly aimed at isolation of the PVs.
Patients with paroxysmal or non-longstanding persistent AF undergoing PVI-only ablation with the option of one repeat PVI in case of AF recurrence were included. An AF burden score (AFB) was determined based on frequency, episode duration, and number of previous cardioversions and then categorized as minimal, mild, moderate, or severe. Two- and three-dimensional anatomical assessment of the left atrium (LA) was performed based on pre-interventional imaging by computed tomography or magnetic resonance imaging.
Of 195 patients analyzed, 24 presented with recurrence after the last intervention (12%, median follow up: 16±11 months). In multivariable analysis, a more than 6-fold increase of risk for AF recurrence was identified for patients with a severe compared to a mild AFB hazard ratio: 6.241 (95% confidence interval: 1.914–20.167, p=0.002). In contrast to univariable analysis, no other parameter was associated with recurrence in multivariable analysis.
Burden-based (AFB) classification was identified as a significant predictor for AF recurrence even after repeat PVI, while neither anatomical parameters nor the established rhythm-based classification of paroxysmal and persistent AF did.
A 53-year-old man with a history of vascular ring repair secondary to a right-sided aortic arch with a retroesophageal subclavian artery and ligamentum arteriosum to the descending thoracic aorta ...presented to our institution with a large aortic pseudoaneurysm of the distal aortic arch. Computed tomography demonstrated a right-sided aortic arch with a 5.8-cm pseudoaneurysm arising from the distal arch with concern for rupture. The patient underwent successful two-stage repair, including a left carotid artery to subclavian artery bypass, followed by total arch replacement with the frozen elephant trunk technique. He recovered well postoperatively, and computed tomography showed complete, successful repair of the pseudoaneurysm.
Objective To evaluate incidence and predictors of early silent bypass occlusion following coronary bypass surgery using cardiac computed tomography angiography. Methods A total of 439 consecutive ...patients with mean age of 66 ± 10 years comprising 17% ( n = 75) females underwent isolated coronary bypass surgery followed by CT scan before discharge. Graft patency was evaluated in 1,319 anastomoses where 44% ( n = 580) arterial and 56% ( n = 739) vein graft anastomosis were performed. Cardiovascular risk factors, demographics, and intraoperative variables were analyzed. We conducted univariable and multivariable logistic regression analyses to analyze variables potentially associated with graft occlusion following CABG. Variables included gender, surgery duration, graft flow, pulsatility index, vein vs. artery graft, and recent MI. Results Overall incidence of graft occlusion was 2.4% (31/1,319), and it was diagnosed in 6.6% (29/439) of patients. The difference in occlusion between arterial (2.1%) and vein (2.6%) grafts was not significant, p = 0.68. The duration of intervention p = 0.034, cross clamp time p = 0.024 as well the number of distal anastomosis p = 0.034 were significantly higher in occlusion group. The univariate and multivariate logistic regression indicated duration of surgery being predictive for bypass graft occlusion with OR = 1.18; 95% CI: 1.01–1.38; p = 0.035. Conclusions Early graft occlusion was associated with surgical factors. The number of distant anastamoses, along duration of surgical intervention were, significantly influenced the risk of EGO. Prolonged procedural time reflecting complex coronary pathology and time-consuming revascularization procedure was as well associated to the elevated risk of occlusion.
We sought to investigate magnetic resonance imaging (MRI) parameters that correspond to vasculitis observed via
FFDG positron emission tomography/computed tomography (PET/CT) and ultrasound in ...patients with large-vessel giant cell arteritis (LV-GCA).
We performed a cross-sectional analysis of patients diagnosed with LV-GCA. Patients were selected if MRI, PET/CT, and vascular ultrasound were performed at the time of LV-GCA diagnosis. Imaging findings in vessel segments (axillary segment per side, thoracic aorta) assessed using at least two methods were compared. Vessel wall thickening, oedema, and contrast agent enhancement were each assessed via MRI.
Twelve patients with newly diagnosed LV-GCA were included (seven females, 58%; median age 72.1, IQR 65.5-74.2 years). The MRI results showed mural thickening in 9/24 axillary artery segments. All but 1 segment showed concomitant oedema, and additional contrast enhancement was found in 3/9 segments. In total, 8 of these 9 segments corresponded to vasculitic findings in the respective segments as observed via PET/CT, and 2/9 corresponded to vasculitis in the respective ultrasound images. If MRI was performed more than 6 days after starting prednisone treatment, thickening and oedema were seen in only 1/24 segments, which was also pathologic according to ultrasound findings but not those obtained via PET/CT. Four patients had mural thickening, oedema, and contrast enhancement in the aorta, among whom three patients also had vasculitic findings observed via PET/CT. Isolated mural thickening in one patient corresponded to a negative PET/CT result.
In the MRI results, mural thickening due to oedema corresponded to vasculitic PET/CT findings but not vasculitic ultrasound findings. The duration of steroid treatment may reduce the sensitivity of MRI.
Echocardiography to Predict AF Recurrence
Background
Arrhythmia recurrence after atrial fibrillation (AF) ablation remains high and requires repeat interventions in a substantial number of patients. ...We assessed the value of conventional and 3‐D echocardiography to predict AF recurrence.
Methods and Results
Consecutive patients undergoing AF ablation by means of pulmonary vein isolation were included in a prospective registry. Echocardiograms were obtained prior to the ablation procedure, and analyzed offline in a standardized manner, including 3‐D left atrial (LA) volumetry and determination of LA function and sphericity. The primary endpoint, AF recurrence (>30 seconds) between 3 to 12 months after AF ablation, was independently adjudicated. We included 276 patients (73% male, mean age 59.9 ± 9.9 years). Paroxysmal and persistent AF were present in 178 (64%) and 98 (36%) patients, respectively. Mean left ventricular ejection fraction and indexed LA volume in 3‐D (LAVI) were 52 ± 12% and 42 ± 13 mL/m2, respectively. AF recurrence was observed in 110 (40%) patients after a single procedure. Median (interquartile range) time to AF recurrence was 123 (92; 236) days. In multivariable Cox regression models, the only predictors for AF recurrence were the minimal, maximal, and indexed 3‐D LA volumes, P = 0.024, P = 0.016, and P = 0.014, respectively. Quartile specific analysis of 3‐D LAVI showed an HR of 1.885 (95%CI 1.066–3.334; P for trend = 0.015) for the highest compared to the lowest quartile.
Conclusion
Our results show the important role of LA volume for the long‐term freedom from arrhythmia after AF ablation. These data also highlight the potential of 3‐D echocardiography in this context and may facilitate patient selection for AF ablation.
Purpose
The purpose of our study was to assess the value of true lumen and false lumen hemodynamics compared to aortic morphological measurements for predicting adverse-aorta related outcomes (AARO) ...and aortic growth in patients with type B aortic dissection (TBAD).
Materials and Methods
Using an IRB approved protocol, we retrospectively identified patients with descending aorta (DAo) dissection at a large tertiary center. Inclusion criteria includes known TBAD with ≥ 6 months of clinical follow-up after initial presentation for TBAD or after ascending aorta intervention for patients with repaired type A dissection with residual type B aortic dissection (rTAAD). Patients with prior descending aorta intervention were excluded. The FL and TL of each patient were manually segmented from 4D flow MRI data, and 3D parametric maps of aortic hemodynamics were generated. Groups were divided based on (1) presence vs. absence of AARO and (2) growth rate ≥ vs. < 3 mm/year. True and false lumen kinetic energy (KE), stasis, peak velocity (PV), reverse/forward flow (RF/FF), FL to TL KE ratio, as well as index aortic diameter were compared between groups using the Mann–Whitney
U
or independent
t
-test.
Results
A total of
n
= 51 patients (age: 58.4 ± 15.0 years, M/F: 31/20) were included for analysis of AARO. This group contained
n
= 26 patients with TBAD and
n
= 25 patients with rTAAD. In the overall cohort, AARO patients had larger baseline diameters, lower FL-RF, FL stasis, TL-KE, TL-FF and TL-PV. Among patients with
de novo
TBAD, those with AAROs had larger baseline diameter, lower FL stasis and TL-PV. In both the overall cohort and in the subgroup of
de novo
TBAD, subjects with aortic growth ≥ 3mm/year, patients had a higher KE ratio.
Conclusion
Our study suggests that 4D flow MRI is a promising tool for TBAD evaluation that can provide information beyond traditional MRA or CTA. 4D flow has the potential to become an integral aspect of TBAD work-up, as hemodynamic assessment may allow earlier identification of at-risk patients who could benefit from earlier intervention.
PDF
